Heating, ventilation and air conditioning (HVAC) systems are provided in automotive vehicles to maintain comfortable environments within passenger compartments. HVAC systems include ducts for supplying air to passenger compartments through openings in the ducts to various stations in the passenger compartments. In vehicles such as vans, station wagons and suvs in which rear seats are provided for three or four additional passengers, it is desirable to provide additional conditioned air for the rear seats.
According to current practice, a rear-most pillar, known in the art as the “D pillar,” is used as a support for a HVAC duct that transmits vent or processed air to rear areas of the passenger compartment. In large suvs auxiliary HVAC systems are used for this purpose, and are offered by manufacturers as either standard or optional equipment in order to provide cooling and heating to rear areas of vehicles. In order to provide desired cooling air flow patterns, chilled air is moved toward the roofs of these vehicles through ducts that run up either “C pillars”, located in front of the rear wheel wells of the vehicles, or up “D pillars”, located behind the rear wheel wells. Currently, this type of duct is mounted adjacent to the outside surface of the pillar, which reduces space within the passenger compartment of the vehicle. Since it is not desirable to decrease the cross-sectional area of either the duct or pillar, there is a need to provide an arrangement for HVAC duct and D pillar assemblages that reduces space consumed by the assemblages while maintaining cross-sectional areas of ducts and pillars. Such needs extend to other duct and frame member assemblages of vehicles in general.